Today, when I was looking the man page of ‘init’, it was pointing to few more man pages as “See init(5) for more details on configuring Upstart.”
Then I noticed there is several such init with numbers. I have never noticed this numbering in the man pages.
A search on this lead to see man page of the man application, which explained the details further..
$ man man NAME man - an interface to the on-line reference manuals DESCRIPTION man is the system's manual pager. Each page argument given to man is normally the name of a program, utility or function. The manual page associated with each of these arguments is then found and displayed. A section, if provided, will direct man to look only in that section of the manual. The default action is to search in all of the available sections, following a pre-defined order and to show only the first page found, even if page exists in several sec- tions. The table below shows the section numbers of the manual followed by the types of pages they contain. 1 Executable programs or shell commands 2 System calls (functions provided by the kernel) 3 Library calls (functions within program libraries) 4 Special files (usually found in /dev) 5 File formats and conventions eg /etc/passwd 6 Games 7 Miscellaneous (including macro packages and conventions), e.g. man(7), groff(7) 8 System administration commands (usually only for root) 9 Kernel routines [Non standard] A manual page consists of several sections. Conventional section names include NAME, SYNOPSIS, CONFIGURATION, DESCRIPTION, OPTIONS, EXIT STATUS, RETURN VALUE, ERRORS, ENVIRONMENT, FILES, VERSIONS, CONFORMING TO, NOTES, BUGS, EXAMPLE, AUTHORS, and SEE ALSO.
And from this stack exchange question, I came to know more usages of man command as following.
- man printf – Shows default man page.
- man -a printf – Shows all available man pages, one by one as you quit each
- man 1 printf – Shows only man page in the corresponding section
- man -k printf – Shows all man pages having printf in name